The demand for wireless communication of voice and data is constantly increasing. Some wireless communication devices can include a transceiver that implements a direct upconversion and downconversion system. Direct upconversion is a system in which an information-carrying baseband signal is mixed directly with a high-frequency local oscillator (LO) carrier signal in a transmitter. The combined radio frequency (RF) signal is amplified and transmitted from the wireless communication device. Likewise, direct downconversion describes a system in which a received RF signal is downconverted by using an LO to remove the carrier signal from the received RF signal in a receiver to obtain the information carrying baseband signal. In either case, the baseband signal can be split into both in-phase (I) and quadrature-phase (Q) components.
Non-linear devices in the transmitter, such as certain types of power amplifiers, can generate unwanted harmonics or intermodulation products in the transmitted signal. Such unwanted harmonics or intermodulation products can, in turn, result in interference with the transmitted signal and/or distortion of the signal at the receiver to which the signal is transmitted. The transmitted signal can be conditioned within the transmitter to compensate for the non-linear devices. As an example, devices have been developed that can implement error vector magnitude (EVM) analysis of the transmit signal. However, such devices can be expensive, and such analysis can be very time consuming.